Geologic Time Line

GEOLOGIC TIME LINE OF EARTH

PALEOZOIC ERA

CAMBRIAN	600-500 million years ago	Algae, and invertebrae similar to jellyfish and worms. The firstshelled animals begin to appear in the Cambrian period. Arthopods, Brachiopods,Trilobytes
ORDOVICIAN	500-440 million years ago	Graptolites, Orthoceras, and primitive fish - the first verterbrates begin to appear.
SILURIAN	440-395 million years ago	The first true plants appear. Crinoids are abundant, and eurypterids- believed to be the first air-breathing animal appears.
DEVONIAN	395-345 million years ago	Fish evolve into more complex animals, sharks and amphibians multiply.
CARBONIFEROUS	345-280 million years ago	Ferns are plentiful and the first reptiles evolve from the amphibians.Spiders, cockroaches, scorpions appear. First animals to live on dry land.
PERMIAN	280-225 million years ago	Reptiles become abundant. Trees similar to the pine develop, trilobytes become extinct.

MESOZOIC ERA

TRIASSIC	225-190 million years ago	The beginning of the dinosaurs. Plant eaters, meat eaters, flying reptiles,and crocodiles.
JURASSIC	190-136 million years ago	The giant dinosaurs developed, as well as abundant plant life and shellfish.Ammonites, lobster, shrimp.
CRETACEOUS	136-65 million years ago	Peak of development, as well as the downfall, of the great dinosaurs.Triceratops, Tyrannosaurus Rex, the giant Pterodactyl. Desiduoustrees.

CENOZOIC ERA

TERTIARY	65-2 million years ago	Mammals develop such as camels, bears, cats, monkeys, rodents, dogs.Grasses, fruit develop like what we have today.
QUATERNARY	2 million years ago to present	More mammals develop, including the now extinct Saber-Toothed Tiger and the Mastadon. Modern man appears.